MAGNETIC TAPE DEVICE AND HEAD TRACKING SERVO METHOD

• US 20180286447A1
• Filed: 03/14/2018
• Published: 10/04/2018
• Est. Priority Date: 03/29/2017
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: OZAWA, Eiki, KASADA, Norihito
• Granted Patent: US 10,546,605 B2
• Time in Patent Office: Days
• CPC Class Codes: G11B 5/00813 magnetic tapes
• CPC Class Codes: G11B 5/3906 Details related to the use of magnetic thin film layers or to their effects
• CPC Class Codes: G11B 5/3909 Arrangements using a magnetic tunnel junction
• CPC Class Codes: G11B 5/584 for track following on tapes
• CPC Class Codes: G11B 5/5926 recorded in separate tracks, e.g. servo tracks
• CPC Class Codes: G11B 5/70 on a base layer
• CPC Class Codes: G11B 5/70615 containing Fe metal or alloys G11B5/70621 takes precedence
• CPC Class Codes: G11B 5/712 characterised by the surface treatment or coating of magnetic particles
• CPC Class Codes: G11B 5/78 Tape carriers

Abstract

The magnetic tape device includes a magnetic tape and a TMR head (servo head), in which the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, an intensity ratio of a peak intensity Int(110) of a diffraction peak of a (110) plane with respect to a peak intensity Int(114) of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, and a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00.

Claims

1. A magnetic tape device comprising:

a magnetic tape; and

a servo head,

wherein the servo head is a magnetic head including a tunnel magnetoresistance effect type element as a servo pattern reading element,

the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support,

the magnetic layer includes a servo pattern,

the ferromagnetic powder is ferromagnetic hexagonal ferrite powder,

an intensity ratio Int(110)/Int(114) of a peak intensity Int(110) of a diffraction peak of a (110) plane with respect to a peak intensity Int(114) of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, and

a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00.

2. The magnetic tape device according to claim 1,

wherein the vertical direction squareness ratio of the magnetic tape is 0.65 to 0.90.

3. The magnetic tape device according to claim 1,

wherein a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.5 nm.

4. The magnetic tape device according to claim 1,

wherein the magnetic tape includes a non-magnetic layer including non-magnetic powder and a binding agent between the non-magnetic support and the magnetic layer.

5. A head tracking servo method comprising:

reading a servo pattern of a magnetic layer of a magnetic tape by a servo head in a magnetic tape device,

wherein the servo head is a magnetic head including a tunnel magnetoresistance effect type element as a servo pattern reading element,

the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support,

the magnetic layer includes the servo pattern,

the ferromagnetic powder is ferromagnetic hexagonal ferrite powder,

an intensity ratio Int(110)/Int(114) of a peak intensity Int(110) of a diffraction peak of a (110) plane with respect to a peak intensity Int(114) of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, and

a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00.

6. The head tracking servo method according to claim 5,

wherein the vertical direction squareness ratio of the magnetic tape is 0.65 to 0.90.

7. The head tracking servo method according to claim 5,

wherein a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.5 nm.

8. The head tracking servo method according to claim 5,

wherein the magnetic tape includes a non-magnetic layer including non-magnetic powder and a binding agent between the non-magnetic support and the magnetic layer.